Covering of wire, thread-like and filamentary material, and the like, with india rubber, gutta-percha, balata, or similar materials or compounds thereof and apparatus therefor



y 1932- D. F TWISS ET AL 7, 7

COVERING OF WIRE, THREAD LIKE AND FILAMENTARY MATERIAL, AND THE LIKE,

WITH INDIA RUBBER, GUTTA PERCHA, BALATA, OR SIMILAR MATERIALS OR COMPOUNDS THEREOF AND APPARATUS THEREFOR Filed Jan. 18. 1928 86 mg agents, uentsa Patented May 10,

1 UNITED STATES PATENT-OFFICE DOUGLAS FRANK T'WIBS EDWARD AIB'IH'I J'B HUB-DRY, OE GI-LID,

ASSIG-M'ORB 1'0 TEE ANODE COVERING- OI' m, THREAD-LIKE AND IILAIENTABY AND m m RUBBER comm IJII'IED 'WI'JE INDIA. DUBBEB, GUTJLA-PEmBALATA, OR SIMILAR IA'I'EBIALS 03- GO!- POUII'DS THEREOF AND API PABA'IUSgTHEBIalNB Application fled January 18, 1928, Serial I0.

This invention consists in an improved ,process and apparatus for providing wire, thread-like and filamentary material with a coating of india-rubber, gutta percha, balata g 'or similar materials or mixtures of the same.

Qne object of this invention is to provide a covering for wire such as copper or tinned copper wire or threads of any material whether single or in groups, or spun, twisted,

1e doubled, plaited, braided and the like which shall be suitable for insulating, rotecting or covering the said wire or threads for electrical or any other purposes. Another object of the invention is to 'form is a rubber coated'thread of circular cross section and a further object is to provide filaments the cores of which are largely absorbed into the coatings during drying and/orvulcanization. Y a

20 According to the invention the improved process consists in causing wire, thread-like or filamentary material to pass through abath containing an aqueous dispersion in the form of a cream or of viscous consistency and 25 comprising india-rubber, gutta percha, balata or similar materials or more than one of said materials, .then drying the coatin and vulcanizing the same if necessary. he dispersions' may be prepared by concentrating natso ural or artificial dispersions or by incorporatin by mixing or agitating, additional materi suchasrotective co oids or stabilizing 9. nts or th and one or more, com

poun in ents comprising reinforcsofteners, vulcanizing i agents, antl-agers colouring matters with aqueous dispersions containing rubber or tubbar like materials and then concentrating the whole by drying. Advantageously the com- 40, pletion of the incorporation of the additional materials by mixing or agitation is effected during the concentration sothat uniform creams are obtained. The mus dispersions may containrubber who y or artially 4 in theform of previouslyzdie'pgrsefvulcanrlibber such as rubber rec imorIaS It will be understood-that the 'termtrubber ntiposition or rubber like materialsas used e follo includes of the g her, be-

umse, m m Greatlrttaln January as, 1937.

A sist of some amorphous colloidal material '1 which can-be drawn out into a very thread for example from a viscdusflui "or solution. It is desirable for this purpose that the filament shall be one which can be absorbed or partially absorbed, into the surrounding rubberlayer subsequent to the coating operation namely during drying or vulcanization processes. Filaments of tacky or resinous ru her or of glue mixed with rubber are typical and give after coating and vulcanization a soft rubbery cord showing no signsof any less extensible core. The tacky;1 or resinous rubber which may be of the Eup orhis or Jelutong or-similar natural types or may be of ordinary Hevea rubber to which a the desired consistency has been imparted by suitable compounding and mastication is, when warm easily drawn intothreads. Filaments of glue can conveniently be produced from aqueous solutions. to which other ingredients, for example, rubber latex, may

have been added if desired. -Oth en viscous materials for exampleartificial silk fibres,

sodium silicate, resins and the like, can be used for a somewhat similar purpose either a 7 alone or mixed with rubber or with rubber 1 latex while natural silk, or cotton or similar material may be employed as the filamentary material; w According to the preferred methodof carrying our invention mto efiect wire-or threadl ke or filamentary material which-it is'desired to coat is, or guided into a bath containing the dispersion with or without the additional. ingredients above referredto. as 'I The orlfilanientary material is passed under a ed roller situated below the level of the to leave the bath rough a suitably shaped ,tube. The tubedast referred to may lzfil'sion and then upwards in solution 0.3 part'of oleic acid, 0.2 part l of dispersion thereby ensuring a smooth and even distribution of the adherent deposit; the constriction also tends to check the accidental passage of air bubbles from thebath into the cup. The wire or filamentary ma- 1! terial issuing from the tube is therefore coated with a fine uniform and smooth deposit. The coated wire or filament is passed through a suitable warm space or essel to dry the deposit. I I

An example of a dispersion suitable for the purpose of this invention is as follows 8 parts of zinc oxide, 2.5 parts of sulphur, lamp black 1, talc 20, whiting 15, paraffin wax 2 (previously emulsified in water), min- 2 eral rubber 1 (previously finely ground), are mixed with 100 parts of water containing 0.1 part of caustic potash, 0.3 part of oleic'acid and 0.3 part of casein; A sufiicient degree of dispersion for this stage can be attained in a so few minutes. Ammonia-preserved latex is then added in suflicient quantity to introduce parts of rubber, caustic potash having been reviously introduced into the latex so that t ie 60 parts of rubber are accompanied 86 by 0.4 part of caustic potash. The whole is then mixed and concentrated by direct evaporation. A concentrationto %-total solids is convenient especially if the product is to be used for dipping operations.

At the completion of the concentration the mixture is allowed to cool, the agitation being still continued whilst ammonia (e.. g., 1 part of concentrated aqueous ammonia of specific 'gravit 0.880), is added; an accelerator in 45 suitab e amount such as 0.3 part of diethylammoniumdiethyldithiocarbamate may, if desired, be introduced at the same time. It is desirable to continue the agitation for a short time e. g. a few minutes until. the am- 50 monia (with any accelerator) is uniformly disglersed.

other example is as follows :20 parts of whiting, 2 parts of zinc oxide, 1 part of organic dye e. g. tolueneazo-naphtol, 1% of sulphur 0.5 part of tetrame thyl thiuram monosulphide, 3 parts of petroleum jelly (emulsified in water), 8 parts of lithopone, are placed in a mixer and concentrator togethervwith 100 parts of water containing 0 casein'and 0.1 part of caustic potash. After a smooth dispersion has been obtained by agitation suflicient latex is added to introduce 64 parts of rubber together with 0.5

'60 part of caustic potash. The whole is then m'ixed under gentle agitation and concentrated to the desired consistency. In any case it is desirable to continue the agitation and mixing action until the final mixture is obtained in a uniform condition. Stable creams containing up to of total solids can be obtained in this way.

Still another xample is :-16 parts of whiting, 25 parts of French chalk, 16 parts of zinc oxide, and 2 parts of sulphur are placed in a mixer-concentrator together with parts of water containing in solution 0.1 part of casein, 0.1 part of oleic acid and 0.05 part of potassium hydroxide.

After a smooth dis ersion has been obtained by agitation s cient latex is added to introduce LO parts of rubber together with 0.5 part of potassium hydroxide. The whole is then mixedunder gently agitation and concentrated to the desired consistency.

Near the end of the concentration 0.5 part .of piperidine piperidinecarbothionolate in 5 parts of water is addedand the agitation and.

taining 60 parts of 'rubber, 2 parts of lamp black, 10 parts of zinc oxide, 10 arts of whiting, 15 parts of French cha 0.5 part of piperidine piperidinecarbothionolate, 0.1

part of casein, 0.1 part of oleic acid and 0.6

part of potassium hydroxide, is made up substaritially as described in the immediatly preceding example.

In order that our said invention may be more clearly understood and readily carried into effect, the same will now be described by way of example with reference to the accompanying diagrammatic drawings, in which Figure 1 is a cross section of the coating apparatus, Figure 2 is a sectional side elevation thereof and Figure 3 isa diagrammatic view showing the general arrangement of the coat: ing apparatus with drying and vulcanizing means. F K Referring particularly to Figures 1 and 2 the wire or thread-like filamentary material 1 is passed, through a suitable orifice 2, downwardly into a bath 3 containing latex 4 whereof the level is shown'at 5. The wire or filament 1 is guided through the latex by a roller 6, suitably grooved as shown at 7, from .whence it passes upwards and out from the bath through a tube preferably of glass constricted as shown at 9, The moving wire or filament 1 drawsa quantity of latex 11 into the cup 10 formed by the constriction 9 and thus the wire or filament finally issues from a small concentric circular surface of latex, thereby ensuring a smooth and'even distribu-' '-tion ofthe adherent. deposit. The constricsage with the deposit of air bubbles from the latex bath.

The deposit is preferably continuously dried and vulcanized. Thus, in the arrangement shown in Figure 3, the wire or filament may be passed upwardly from the bath 3 through a tubular drying chamber 12, over a pulley 13 and downwardly through a tubular Vulca-nizing chamber 14.

The chambers 12 and 14 are preferably suitably acketed for the circulation of heating fluid such as steam or Water, and provision may also be made to maintain the columns of air within the said chambers in circulation also. In general, however, it will be understood that we do not confine ourselves to any particular treatment of the Wire or filament subsequent to thecoating, the scheme illustrated diagrammatically in Figure 3 being given merely by way of example.

Having now particularly described and ascertained the nature of our said invention and in what manner the same is to be performed, we declare that what we claim is 1. A process of coating filamentary materials uniformly with a rubber composition which comprises passing the material through a bath of a viscous dispersion of rubber constituents, and withdrawing the filamentary material and the dispersion materials adhering thereto through a restrlction and thence centrally through a limited body of said dispersion material and centrally through the surface of said limited body of dispersion material.

2. A process of coating filamentary materials uniformly with a rubber composition which comprises passing the material through a bath of a viscous dispersion of rubber constituents, withdrawing the filamentary material and the dispersion materials adhering thereto through a restriction and thence centrally through a limited body of said dispersion material and centrally through the surface of said limited body of dispersion material, and vulcanizing said filamentary material and adhering rubber composition.

3. A process of coating filamentary materials uniformly with a rubber composition which comprises passing the 'material through a .bathof a viscous dispersion of rubber constituents, withdrawing the filamentary material and the dispersion materials adhering thereto through a restriction and thence centrally through a limited body of said dispersion material and centrally through the surface of said limited body of dispersion material, and vulcanizing said filamentary material and the dispersion constituents adhering thereto under such conditions as to cause an absorption of said filamentary material in said dispersion constituents.

In testimony whereof we aflix our signatures. 

